johu: Is it possible to make the STM32 supply a approx. 20Hz (10-60Hz) signal with adjustable (preferably from the web interface) pulse width on pin3 or pin4? The reason being to control the output voltage from the DC/DC, viewtopic.php?p=30722#p30722
Is it also possible to get the other available pin to be the enable signal? Right now I'm using the "main relay" signal with a RC-delay but would be nice if it could use a separate pin with a adjustable delay from when "main relay" is on.
johu: Is it possible to make the STM32 supply a approx. 20Hz (10-60Hz) signal with adjustable (preferably from the web interface) pulse width on pin3 or pin4? The reason being to control the output voltage from the DC/DC, viewtopic.php?p=30722#p30722
Is it also possible to get the other available pin to be the enable signal? Right now I'm using the "main relay" signal with a RC-delay but would be nice if it could use a separate pin with a adjustable delay from when "main relay" is on.
I recommend you just use Enable signal from a relay and add a 555 astable timer to Enable signal to provide 20Hz. You put this on the 2nd key position (1st beeing the radio on and 3rd for starter actuator). This way your aux systems will have power if you need to turn them on separately from inverter.
I am making a similar setup with my Volt gen2 DCDC which needs 110Hz 70% duty pwm to give 14.2Vdc. I will start my 555 pwm generator on Enable signal.
555 is also capable of working with 14Vdc directly.
johu: Is it possible to make the STM32 supply a approx. 20Hz (10-60Hz) signal with adjustable (preferably from the web interface) pulse width on pin3 or pin4? The reason being to control the output voltage from the DC/DC, viewtopic.php?p=30722#p30722
Is it also possible to get the other available pin to be the enable signal? Right now I'm using the "main relay" signal with a RC-delay but would be nice if it could use a separate pin with a adjustable delay from when "main relay" is on.
I recommend you just use Enable signal from a relay and add a 555 astable timer to Enable signal to provide 20Hz. You put this on the 2nd key position (1st beeing the radio on and 3rd for starter actuator). This way your aux systems will have power if you need to turn them on separately from inverter.
I am making a similar setup with my Volt gen2 DCDC which needs 110Hz 70% duty pwm to give 14.2Vdc. I will start my 555 pwm generator on Enable signal.
555 is also capable of working with 14Vdc directly.
For my own purposes I use the 328p already on the pcb with modified SW and the AC-precharge output to generate the signal I need. Works fine for me but I'm trying to create a more permanent solution that everybody can use. So trying to use the STM32 if possible, and then only add some transistors.
Pin3 is PC14 and Pin4 is PC15.
PB9 looks to be unused on the Toyota boards I've looked at so should be ok to use.
Any other pin available that can be used as a delayed DC/DC enable signal pin? It would be nice to have a selectable delay from "main contactor" enable to DC/DC enable. Can be solved by using RC-delay but more adjustable if done in SW. What is your opinion, RC-delay or SW based?
I will then create a suggested HW for this and send to Damien for implementation on Toyota boards.
Precharge pin could be used for enabling. Precharge is enabled right at startup (could even be enabled by the bootloader, optionally) and will pull IGCT low. When inverter is starting precharge drop out and DC-DC would enable. Precharge dropout can also be delayed.
Tested the precharge idea, works I'm pulling up IGCT with a 2W 680 Ohm resistor and letting the precharge relay driver pull it low. As soon as start signal is issued the DC/DC converter starts.
Also instructing the boot loader to engage precharge, as in my case precharge is on as soon as I switch the car on. That would lead to the DC/DC converter briefly switching on at startup and also during software update. Maybe not good for the precharge resistor.
Elegant solution with very little added components but the drawback of having no control in certain situations makes me want to add some more components.
Maybe better using main contactor output and 180jacob:s idea, but that will increase the BOM with one p-fet. I would also use LBSS84LT1G instead as it has higher Vgs voltage (20V), but not in stock at jlcpcb... viewtopic.php?p=19902#p19902
Or maybe like this, no new parts but haven't figured out the time delay part yet...
Screenshot_2021-08-20_18-40-55.png (6.01 KiB) Viewed 2554 times
I'm pulling up IGCT with a 2W 680 Ohm resistor and letting the precharge relay driver pull it low. As soon as start signal is issued the DC/DC converter starts.